Core and mold units for casting concrete posts and a post formed thereby



April 7, 1964 E. C. KARSTEDT CORE AND MOLD UNITS FOR CASTING CONCRETEPOSTS AND A POST FORMED THEREBY Filed Jan. 12, 1960 INVENTOR. ELMER C.KARSTEDT United States Patent O 3,127,702 CRE AND M011) UNITES FGRCASTING CGN- CRETE PSTS AND A PST FURMED THEREBY Eimer C. Karstadt, 640McHenry St., Burlington, Wis. Fiied .la 12, 1960, Ser. No. 1,991 1Ciaim. (Cl. Sti- 321) This invention relates to improvements in core andmold units for casting concrete posts and a post formed thereby, andmore particularly to an inexpensive and efficient device for forming animproved type of concrete post.

Presently, posts formed of concrete are used only sparingly in thebuilding industry for the reason that such posts are relativelyexpensive to manufacture, and for the further reason that it is diicultto anchor or support other structural members on such posts, theconcrete forming a very unsatisfactory base for nails or similarfastening devices. With these deciencies of conventional concrete postsin mind, therefore, the principal objects of the present invention areto provide an improved core and mold unit for concrete posts wherein thecost of manufacturing such posts is substantially reduced, and whereinthe finished posts are adapted to receive and securely retain nails orother fastening devices.

A more specic object of the present invention is to provide a core andmold unit formed of an inexpensive pre-fabricated material, the cost ofwhich unit is minute in comparison to the steel molds presently used inthe manufacture of concrete posts.

A further specic object of the present invention is to provide aprefabricated core and mold unit for concrete posts, and the post formedthereby, wherein the core members become an integral part of theiinished post.

A further specific object is to provide an improved type of concretepost having integral means `formed therein for receiving and securelyretaining nails or other fastening devices.

A further object is to provide an inexpensive core and mold unit forconcrete posts, as described, wherein the mold also functions as ashipping container or carton for the finished post.

A further object of the invention is to provide means for forming animproved type of concrete post, which post requires substantially lessconcrete than conventional posts of comparable strength and durability,and which light-weight post is relatively cheap to transport.

With the above and other objects in View, the invention consists of theimproved core and mold unit for concrete posts and a post formedthereby, and all of its parts and combinations7 as set forth in theclaim, and all equivalents thereof.

In the accompanying drawing, wherein the same reference charactersdesignate the same parts in all of the views:

FIG. 1 is a top plan view of the core and mold unit comprising thepresent invention;

FIG. 2 is a longitudinal sectional view of the unit, taken along line2-2 of FG. l;

FlG. 3 is a transverse sectional view through a concrete post formed bythe improved core and mold unit, showing nails driven into said post;and

FIG. 4 is a fragmentary longitudinal sectional view of the post, takenalong line 4-4 of FIG. 3.

Referring now more particularly to FIGS. 1 and 2 of the drawing, it willbe seen that the core and mold unit comprising the present inventioninclude an elongated cylindrical shell 10, which is constructed ofpaperboard or the like, and which member comprises the mold portion ofthe unit. Positioned within said shell is ice a diametrically disposedcentral wall 11, preferably at least 1/2 inch in thickness, and formedof similar material, and a pair 0f elongated hollow tubes 12 and 13,said wall and tube members forming the core element of the unit.

`It is to be understood that while the foregoing members are describedas being made of paperboard, other inexpensive materials includingrubber, wood, or a plastic such as polystyrene might also be employed,the important characteristic of the material being its relatively smallcost in comparison to the steel molds ordinarily used in casting forms.Moreover, with respect to the wall member 11, it is essential, as willbe hereinafter seen, that the material be relatively soft so that it canibe readily penetrated by a nail or the like, and that it havesufficient cohesive qualities so that it will not crumble or deterioratewhen a nail is driven into the same, as `frequently occurs with arelatively brittle substance like concrete.

Referring now to FIGS. l and 3, the above mentioned wall member 11 isprovided with a series of vertical channels or grooves 14, which arealternately spaced on opposite sides of the wall. The longitudinal edges0f said wall abut the inner surface of the cylindrical outer shell 1oand when the latter is removed from the finished post, the edge faces ofsaid wall are flush with and become part of the post exterior surface,forming diametrically-opposed, longitudinal strips into which nails,staples, or other fastening devices may be driven, as will behereinafter described in greater detail.

As shown in FIG. 2, the wall 11 is also provided with a series oflongitudinally-spaced, central openings or holes 15 therethrough, whichopenings comprise about of the total surface area of said wall in theillustrated form of the invention. The purpose of said openings is toprevent the wall from functioning as a divider between the two halfsections of the post, the concrete extending through said openings tojoin said sections in the finished post.

The internal tubes 12 and 13 are mounted on each side of the wall member11, and as will be seen in FIG. l, said tubes are clamped against saidwall and held in position by means of a plurality of retaining wires 17which pass thereabout and through the aforementioned wall openings 1S.It is to be understood that while two interior tubes 12 and 13 areillustrated, a greater number might be preferred and the invention isnot to be limited in this respect. The purpose of said interior tubes,of course, is to provide hollow spaces in the post interior, therebyconserving concrete and lessening the weight of the finished post. Theresult is a post that is not only more economical to manufacture,requiring less concrete than conventional posts, but a post that becauseof its lightness is comparatively inexpensive to transport.

In addition to the wires 17, which are designed to maintain the tubes 12and 13 in position, as described, each of said tubes is also providedwith a crimped wire 16 which encircles the same in a spiral manner andwhich adds strength and rigidity to said tubes. It has been found thatby crimping said wires the concrete lill is peritted to form around thesame so that they are completely embedded and firmly retained in theconcrete. As will be appreciated, the presence of steel wires, 16 and17, provides increased strength and renders the post more durable thanan all-concrete post.

The complete core and mold unit also includes a cap 18 mounted on eachend of the hollow tube members 12 and 13. The purpose of said caps, ofcourse, is to prevent concrete from entering the tubes during thepouring operation, and the exact design of said members is not critical.In this respect, it is to be understood that the sameis also true of theother components hereinabove described, and the invention is not to belimited to the exact design of said structures. It is possible, byfollowing the teachings of the present invention, for example, to formposts of square or other cross-sectional shapes, as well as'thecylindrical post illustrated.

In the use of the core and mold unit comprising the present invention,the concrete 20 is merely poured in through the top of the shell in theconventional manner and fills up the spaces within the mold not occupiedby the core elements. After the concrete has hardened or set, the outershell 10 can be removed, although this is not necessary and said outermember can be left on the finished post to serve as a protective coverduring shipment. As herebefore mentioned, the inner or core members,including the central wall 11 and the hollow interior tubes 12 and 13are left in the concrete and become an integral part of the postinterior, providing a post which is a combination of concrete and wirereinforced paperboard or plastic material.

The edge portions of the central wall member 11 are flush with the outersurface of the finished post and provide diametrically opposed stripsextending the entire length of the post. As will be seen in FIGS. 3 and4, the wall member 11 thus provides means on two sides of the post intowhich nails, staples or other fastening members may be driven. As shownin FIG. 3, a nail 19 driven into said relatively soft Wall member isdefiected by the alternate concrete ridges or protrusions 14' which areformed by the hardened concrete ll in the aforementioned channels 14.The effect is that a nail, when driven into the post its full length, iscrimped and becomes securely held in said post. n

The uses and advantages of the nail-receiving means formed in thepresent posts are, of course, numerous. In conventional concrete posts,it is not only difficult to drive a nail into the post, but a nail whichis driven therein will not hold and can be easily pulled from itsmounting. With the present invention, however, due to the aforementionedcrimping action of the alternate protrusions 14', nails or the like aresecurely retained in the post. The result is that the present inventionmakes the use of concrete posts practical for many construction purposesheretofore impossible. This is particularly irnportant, of course, inthose areas of the World where wood and steel are relatively expensiveand the use of concrete has definite economic advantages.

Additional advantages of the present core and mold device are that theinexpensive nature of the unit permits any concrete productsmanufacturer to cast a concrete post without the investment in expensivesteel molds. Moreover, the present unit is extremely light in Weight andcan be shipped long distances for relatively little cost.

In addition -to the shipping advantages of the 1ight- Weight core landmold unit, the weight of the finished posts is also considerably lessthan that of conventional concrete posts and permits the relativelycheap shipment of said posts. Moreover, of course, posts manufactured inaccordance with the present invention require less concrete thanconventional posts of comparable size and strength and are substantiallyless costly to manufacture.

From the foregoing, it will be seen that the present invention providesmeans for manufacturing concrete posts, wherein the core and mold deviceis not only novel, but wherein the resulting post has definiteadvan-tages over conventional concrete posts. It is to be understood,however, that various changes and modifications may be made in both thecore and mold unit as above described and in the finished product,without departing from the spirit of the invention, and all of changesor modifications are contemplated as may come Within the scope of thefollowing claim.

What I claim is:

In a concrete post, an integral core unit comprising: an upright,rectangular wall-like core member extending substantially the entirelength of t-he post, said core member having a plurality of relativelylarge ytransverse openings therethrough, and having a plurality ofchanneled grooves adjacent each longitudinal edge spaced alternately onopposite sides thereof, said grooves extending the entire length of saidwall-like core member, and said grooves extending inwardly at least halfthe thickness of said core member, the longitudinal edges of said coremember being flush with the exterior surface of the post to receivedriven yfastening elements; a pair of elongated hollow tubes disposedvertically adjacent the opposite sides of said wall-like core members;closures on the ends vof said tubes; crimped wire reinforcing meansencircling `said tubes in spiral fashion along substantially theirentire length; and Wire retaining means extending through the openingsin said wall-like core member and arranged to clampingly support saidtubes against the opposite sides of said core member and to also providereinforcement in the post interior, the concrete of the post surroundingsaid core andtube members and filling the spaces therebetween.

References Cited in the file of this patent UNITED STATES PATENTS721,224 Patton Feb. 24, 1903 869,724 Nichols Oct. 29, 1907 966,274Wainwright et al. Aug. 2, 1910 1,016,151 Huber Jan. 30, 1912 1,187,600Basham .Tune 20, 1916 1,254,205 yCosby Jan. 22, 1918 1,387,066 MurrayA-ug. 9, 1921 1,648,387 Gustaveson Nov. 8, 1927 2,126,394 Jansen Aug. 9,1938 2,618,037 Miller Nov. 18, 1952 2,701,905 Sullivan Feb. 15, 1955FOREIGN PATENTS '249,007 Great Britain of 1926 385,419 Great BritainDec. 29, 1932 OTHER REFERENCES Engineering News-Record (a publication),Ian. 31, 1957, page 52. (Copy in Div. 33.)

